Polarizing film, display device and production process thereof

Patent metadata

Field	Value
Publication number	US-10047294-B2
Application number	US-201615172282-A
Country	US
Kind code	B2
Filing date	Jun 3, 2016
Priority date	Mar 31, 2010
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Provided is a polarizing film showing high dichroism comprising a substrate, and a photo alignment film and a light absorption anisotropic film laminated on the substrate in this order. The light absorption anisotropic film is obtained by fixing the alignment of a dichroic dye composition comprising at least one nematic liquid crystalline azo dichroic dye and in X-ray diffraction measurement thereof, diffraction peaks derived from periodic structure along a vertical direction to the alignment axis are present, the period indicated by at least one of the diffraction peaks is 3.0 to 15.0 Å and an intensity of the diffraction peak does not show a maximum value in the range of ±70° of the film normal line direction in a plane vertical to the alignment axis.

First claim

The invention claimed is:

1. A polarizing film comprising a substrate, and an optical alignment film and an optical absorption anisotropic film laminated on the substrate in this order,
wherein the optical absorption anisotropic film is obtained by fixing the alignment of a dichroic dye composition comprising two or more nematic liquid crystalline dichroic dyes, wherein the dichroic dyes have a molecular length of 17 Å or more and an aspect ratio of 1.7 or more;
in X-ray diffraction measurement thereof, diffraction peaks derived from periodic structure along a vertical direction to the alignment axis are present, the period indicated by at least one of the diffraction peaks is 3.0 to 15.0 Å and an intensity of the diffraction peak does not show a maximum value in the range of ±70° of the film normal line direction in a plane vertical to the alignment axis; and
wherein said dichroic dye composition comprises two or more dichroic dyes which are selected from dichroic dyes represented by the following formula (II), the following formula (III), the following formula (IV) or the following formula (VI):

wherein, R 21 and R 22 each represent a hydrogen atom, an alkyl group, an alkoxy group or a substituent represented by -L 22 -Y, provided that, at least one of them represents a group other than a hydrogen atom; L 22 represents an alkylene group, and one CH 2 group or non-adjacent two or more CH 2 groups present in the alkylene group may each be substituted with —O—, —COO—, —OCO—, —OCOO—, —NRCOO—, —OCONR—, —CO—, —S—, —SO 2 —, —NR—, —NRSO 2 — or —SO 2 NR— and R represents a hydrogen atom or an alkyl group having 1 to 4 carbons; Y represents a hydrogen atom, a hydroxy group, an alkoxy group, a carboxyl group, a halogen atom or a polymerizable group; L 21 s each represent a linking group selected from the group consisting of an azo group (—N═N—), a carbonyloxy group (—C(═O)O—), an oxycarbonyl group (—O—C(=O)—), an imino group (—N═CH—) and a vinylene group (—C═C—); Dye each represents an azo dye residue represented by the following formula (IIa);

in the formula (IIa), * represents a linkage part to L 21 ; X 21 represents a hydroxy group, a substituted or un-substituted alkyl group, a substituted or un-substituted alkoxy group, an un-substituted amino group or a mono or dialkylamino group; Ar 21 s each represent an aromatic hydrocarbon ring group optionally having a substituent or aromatic heterocyclic group optionally having a substituent; n represents an integer of 1 to 3, and when n is 2 or more, two Ar 21 s may be mutually the same or different;

wherein, R 31 to R 35 each represent independently a hydrogen atom or a substituent; R 36 and R 37 each represent independently a hydrogen atom or an alkyl group optionally having a substituent; Q 31 represents an aromatic hydrocarbon group optionally having a substituent, aromatic heterocyclic group optionally having a substituent or cyclohexane ring group optionally having a substituent; L 31 represents a divalent linking group; A 31 represents an oxygen atom or a sulfur atom;

wherein, R 41 and R 42 each represent a hydrogen atom or a substituent, and may be mutually linked to form a ring; Ar 4 represents an optionally substituted divalent aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group; R 43 and R 44 each represent a hydrogen atom or an optionally substituted alkyl group, and may be mutually linked to form a hetero ring;

wherein, A 1 and A 2 each represent independently a substituted or un-substituted hydrocarbon ring group or a substituted or un-substituted hydrocarbon heterocyclic group.

2. The polarizing film according to claim 1 , wherein at least one diffraction peak of said optical absorption anisotropic film is a diffraction peak derived from the periodic structure along the inplane direction.

3. The polarizing film according to claim 1 , wherein said optical absorption anisotropic film shows diffraction peaks derived from the periodic structure along a direction parallel to the alignment axis in X-ray diffraction measurement thereof.

4. The polarizing film according to claim 3 , wherein the period indicated by at least one of said diffraction peaks is 3.0 to 50.0 Å.

5. The polarizing film according to claim 1 , wherein the half-value width of at least one of said diffraction peaks is 1.0 Å or less.

6. The polarizing film according to claim 1 , wherein at least one diffraction peak of said optical absorption anisotropic film is a diffraction peak derived from the periodic structure along the inplane direction, and said optical absorption anisotropic film shows diffraction peaks derived from the periodic structure along a direction parallel to the alignment axis in X-ray diffraction measurement thereof.

7. The polarizing film according to claim 1 , wherein at least one diffraction peak of said optical absorption anisotropic film is a diffraction peak derived from the periodic structure along the inplane direction, and the half-value width of at least one of said diffraction peaks is 1.0 Å or less.

8. The polarizing film according to claim 1 , wherein at least one diffraction peak of said optical absorption anisotropic film is a diffraction peak derived from the periodic structure along the inplane direction, said optical absorption anisotropic film shows diffraction peaks derived from the periodic structure along a direction parallel to the alignment axis in X-ray diffraction measurement thereof, and the period indicated by at least one of said diffraction peaks is 3.0 to 50.0 Å.

9. The polarizing film according to claim 1 , wherein at least one diffraction peak of said optical absorption anisotropic film is a diffraction peak derived from the periodic structure along the inplane direction, said optical absorption anisotropic film shows diffraction peaks derived from the periodic structure along a direction parallel to the alignment axis in X-ray diffraction measurement thereof, and the half-value width of at least one of said diffraction peaks is 1.0 Å or less.

10. A display device comprising the polarizing film according to claim 1 .

11. A process for producing the polarizing film according to claim 1 , comprising at least the following [1] to [3] in this order;
[1] irradiating an optical alignment film formed on a substrate,
[2] coating a dichroic dye composition dissolved in an organic solvent on the optical alignment film, and
[3] aligning the coated film of the dichroic dye composition by heating at 50° C. or higher and 250° C. or lower to give an optical absorption anisotropic film.

Assignees

• Fujifilm Corp

Inventors

• Morishima Shinichi
• Iwahashi Nobutaka
• Ogiyama Masashi
• Uemura Minoru

Classifications

• G02B5/3016

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• C09B31/30

  Other polyazo dyes · CPC title

• C09B29/083

  having -N< (in a ring) · CPC title

• C09B31/18

  from a coupling component "D" containing a directive amine group · CPC title

• C09B29/081

  unsubstituted alkylamino, alkenylamino, alkynylamino, cycloalkylamino, aralkylamino or arylamino · CPC title